期刊文献+
共找到1,215篇文章
< 1 2 61 >
每页显示 20 50 100
Automated recognition of rock discontinuity in underground engineering using geometric feature analysis
1
作者 Adili Rusuli Xiaojun Li +1 位作者 Yuyun Wang Yi Rui 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第2期1016-1033,共18页
Discontinuities in rock masses critically impact the stability and safety of underground engineering.Mainstream discontinuities identificationmethods,which rely on normal vector estimation and clustering algorithms,su... Discontinuities in rock masses critically impact the stability and safety of underground engineering.Mainstream discontinuities identificationmethods,which rely on normal vector estimation and clustering algorithms,suffer from accuracy degradation,omission of critical discontinuities when orientation density is unevenly distributed,and need manual intervention.To overcome these limitations,this paper introduces a novel discontinuities identificationmethod based on geometric feature analysis of rock mass.By analyzing spatial distribution variability of point cloud and integrating an adaptive region growing algorithm,the method accurately detects independent discontinuities under complex geological conditions.Given that rock mass orientations typically follow a Fisher distribution,an adaptive hierarchical clustering algorithm based on statistical analysis is employed to automatically determine the optimal number of structural sets,eliminating the need for preset clusters or thresholds inherent in traditional methods.The proposed approach effectively handles diverse rock mass shapes and sizes,leveraging both local and global geometric features to minimize noise interference.Experimental validation on three real-world rock mass models,alongside comparisons with three conventional directional clustering algorithms,demonstrates superior accuracy and robustness in identifying optimal discontinuity sets.The proposed method offers a reliable and efficienttool for discontinuities detection and grouping in underground engineering,significantlyenhancing design and construction outcomes. 展开更多
关键词 Underground engineering Rock mass discontinuity Orientation grouping Fisher distribution 3D point cloud Automated recognition
在线阅读 下载PDF
Transformer-Driven Multimodal for Human-Object Detection and Recognition for Intelligent Robotic Surveillance
2
作者 Aman Aman Ullah Yanfeng Wu +3 位作者 Shaheryar Najam Nouf Abdullah Almujally Ahmad Jalal Hui Liu 《Computers, Materials & Continua》 2026年第4期1364-1383,共20页
Human object detection and recognition is essential for elderly monitoring and assisted living however,models relying solely on pose or scene context often struggle in cluttered or visually ambiguous settings.To addre... Human object detection and recognition is essential for elderly monitoring and assisted living however,models relying solely on pose or scene context often struggle in cluttered or visually ambiguous settings.To address this,we present SCENET-3D,a transformer-drivenmultimodal framework that unifies human-centric skeleton features with scene-object semantics for intelligent robotic vision through a three-stage pipeline.In the first stage,scene analysis,rich geometric and texture descriptors are extracted from RGB frames,including surface-normal histograms,angles between neighboring normals,Zernike moments,directional standard deviation,and Gabor-filter responses.In the second stage,scene-object analysis,non-human objects are segmented and represented using local feature descriptors and complementary surface-normal information.In the third stage,human-pose estimation,silhouettes are processed through an enhanced MoveNet to obtain 2D anatomical keypoints,which are fused with depth information and converted into RGB-based point clouds to construct pseudo-3D skeletons.Features from all three stages are fused and fed in a transformer encoder with multi-head attention to resolve visually similar activities.Experiments on UCLA(95.8%),ETRI-Activity3D(89.4%),andCAD-120(91.2%)demonstrate that combining pseudo-3D skeletonswith rich scene-object fusion significantly improves generalizable activity recognition,enabling safer elderly care,natural human–robot interaction,and robust context-aware robotic perception in real-world environments. 展开更多
关键词 Human object detection elderly care RGB-based pose estimation scene context analysis object recognition Gabor features point cloud reconstruction
在线阅读 下载PDF
Hand Gesture Recognition Using Appearance Features Based on 3D Point Cloud 被引量:2
3
作者 Yanwen Chong Jianfeng Huang Shaoming Pan 《Journal of Software Engineering and Applications》 2016年第4期103-111,共9页
This paper presents a method for hand gesture recognition based on 3D point cloud. Digital image processing technology is used in this research. Based on the 3D point from depth camera, the system firstly extracts som... This paper presents a method for hand gesture recognition based on 3D point cloud. Digital image processing technology is used in this research. Based on the 3D point from depth camera, the system firstly extracts some raw data of the hand. After the data segmentation and preprocessing, three kinds of appearance features are extracted, including the number of stretched fingers, the angles between fingers and the gesture region’s area distribution feature. Based on these features, the system implements the identification of the gestures by using decision tree method. The results of experiment demonstrate that the proposed method is pretty efficient to recognize common gestures with a high accuracy. 展开更多
关键词 Human-Computer-Interaction Gesture recognition 3D point Cloud Depth Image
在线阅读 下载PDF
Recognition Method for Change Point of Traffic Flow Linear Regressions
4
作者 张敬磊 王晓原 马立云 《Journal of Donghua University(English Edition)》 EI CAS 2012年第1期59-61,共3页
Recognition method of traffic flow change point was put forward based on traffic flow theory and the statistical change point analysis of multiple linear regressions. The method was calibrated and tested with the fiel... Recognition method of traffic flow change point was put forward based on traffic flow theory and the statistical change point analysis of multiple linear regressions. The method was calibrated and tested with the field data of Liantong Road of Zibo city to verify the validity and the feasibility of the theory. The results show that change point method of multiple linear regression can make out the rule of quantitative changes in traffic flow more accurately than ordinary methods. So, the change point method can be applied to traffic information management system more effectively. 展开更多
关键词 traffic flow quantitative changes multiple linear regressions change point recognition
在线阅读 下载PDF
WADE-Net: Weighted Aggregation with Density Estimation for Point Cloud Place Recognition
5
作者 Ke Liu Xing Wang +2 位作者 Yaxin Peng Zhen Ye Chaozheng Zhou 《Advances in Pure Mathematics》 2021年第5期502-523,共22页
Point cloud based place recognition plays an important role in mobile robotics. In this paper, we propose a weighted aggregation method from structure information adaptively for point cloud place recognition. Firstly,... Point cloud based place recognition plays an important role in mobile robotics. In this paper, we propose a weighted aggregation method from structure information adaptively for point cloud place recognition. Firstly, to preserve the prior distributions and local geometric structures, we fuse learned hidden features with handcrafted features in the beginning. Secondly, we further extract and aggregate adaptively weighted features concerning density and relative spatial information from these fused features, named Weighted Aggregation with Density Estimation (WADE) module. Then, we conduct the WADE block iteratively to group the latent manifold structures. Finally, comparison results on two public datasets Oxford Robotcar and KITTI show that the proposed approach exceeds the comparison approaches on recall rate averagely 7% - 8%. 展开更多
关键词 point Cloud Place recognition Deep Learning Feature Extraction
在线阅读 下载PDF
PT-MFR:一种基于Point Transformer的CAD模型加工特征识别方法
6
作者 何皓辰 方正 +2 位作者 卢政达 肖俊 王颖 《中国科学院大学学报(中英文)》 北大核心 2026年第1期115-124,共10页
加工特征识别在计算机辅助设计(CAD)和制造(CAM)中至关重要,是连接CAD和CAM系统的重要环节。研究者们提出了基于规则和基于学习的2类加工特征识别方法,其中基于学习的方法表现更出色且备受关注。然而,现有识别方法面临着几何信息利用不... 加工特征识别在计算机辅助设计(CAD)和制造(CAM)中至关重要,是连接CAD和CAM系统的重要环节。研究者们提出了基于规则和基于学习的2类加工特征识别方法,其中基于学习的方法表现更出色且备受关注。然而,现有识别方法面临着几何信息利用不足、加工特征定位不精准、实例分割过程复杂等挑战。针对这些问题,提出PT-MFR,一种基于Point Transformer的CAD模型加工特征识别方法,它执行语义分割和实例分割2个任务,分别预测模型每个面的加工特征语义类别并计算面相似度以分割加工特征实例,综合2个任务得到加工特征识别结果。实验结果表明,提出的方法性能优于现有的其他方法。 展开更多
关键词 加工特征识别 点云 神经网络 point Transformer
在线阅读 下载PDF
An enhanced segmentation method for 3D point cloud of tunnel support system using PointNet++t and coverage-voted strategy algorithms
7
作者 Wenju Liu Fuqiang Gao +4 位作者 Shuangyong Dong Xiaoqing Wang Shuwen Cao Wanjie Wang Xiaomin Liu 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第2期1653-1660,共8页
3D laser scanning technology is widely used in underground openings for high-precision,rapid,and nondestructive structural evaluations.Segmenting large 3D point cloud datasets,particularly in coal mine roadways with m... 3D laser scanning technology is widely used in underground openings for high-precision,rapid,and nondestructive structural evaluations.Segmenting large 3D point cloud datasets,particularly in coal mine roadways with multi-scale targets,remains challenging.This paper proposes an enhanced segmentation method integrating improved PointNet++with a coverage-voted strategy.The coverage-voted strategy reduces data while preserving multi-scale target topology.The segmentation is achieved using an enhanced PointNet++algorithm with a normalization preprocessing head,resulting in a 94%accuracy for common supporting components.Ablation experiments show that the preprocessing head and coverage strategies increase segmentation accuracy by 20%and 2%,respectively,and improve Intersection over Union(IoU)for bearing plate segmentation by 58%and 20%.The accuracy of the current pretraining segmentation model may be affected by variations in surface support components,but it can be readily enhanced through re-optimization with additional labeled point cloud data.This proposed method,combined with a previously developed machine learning model that links rock bolt load and the deformation field of its bearing plate,provides a robust technique for simultaneously measuring the load of multiple rock bolts in a single laser scan. 展开更多
关键词 point cloud segmentation Improved pointNet++ Tunnel laser scanning Rock bolt automatic recognition
在线阅读 下载PDF
Pre-process algorithm for satellite laser ranging data based on curve recognition from points cloud
8
作者 Liu Yanyu Zhao Dongming Wu Shan 《Geodesy and Geodynamics》 2012年第2期53-59,共7页
The satellite laser ranging (SLR) data quality from the COMPASS was analyzed, and the difference between curve recognition in computer vision and pre-process of SLR data finally proposed a new algorithm for SLR was ... The satellite laser ranging (SLR) data quality from the COMPASS was analyzed, and the difference between curve recognition in computer vision and pre-process of SLR data finally proposed a new algorithm for SLR was discussed data based on curve recognition from points cloud is proposed. The results obtained by the new algorithm are 85 % (or even higher) consistent with that of the screen displaying method, furthermore, the new method can process SLR data automatically, which makes it possible to be used in the development of the COMPASS navigation system. 展开更多
关键词 satellite laser ranging (SLR) curve recognition points cloud pre-process algorithm COM- PASS screen displaying
原文传递
Study of Human Action Recognition Based on Improved Spatio-temporal Features 被引量:7
9
作者 Xiao-Fei Ji Qian-Qian Wu +1 位作者 Zhao-Jie Ju Yang-Yang Wang 《International Journal of Automation and computing》 EI CSCD 2014年第5期500-509,共10页
Most of the exist action recognition methods mainly utilize spatio-temporal descriptors of single interest point while ignoring their potential integral information, such as spatial distribution information. By combin... Most of the exist action recognition methods mainly utilize spatio-temporal descriptors of single interest point while ignoring their potential integral information, such as spatial distribution information. By combining local spatio-temporal feature and global positional distribution information(PDI) of interest points, a novel motion descriptor is proposed in this paper. The proposed method detects interest points by using an improved interest point detection method. Then, 3-dimensional scale-invariant feature transform(3D SIFT) descriptors are extracted for every interest point. In order to obtain a compact description and efficient computation, the principal component analysis(PCA) method is utilized twice on the 3D SIFT descriptors of single frame and multiple frames. Simultaneously, the PDI of the interest points are computed and combined with the above features. The combined features are quantified and selected and finally tested by using the support vector machine(SVM) recognition algorithm on the public KTH dataset. The testing results have showed that the recognition rate has been significantly improved and the proposed features can more accurately describe human motion with high adaptability to scenarios. 展开更多
关键词 Action recognition spatio-temporal interest points 3-dimensional scale-invariant feature transform (3D SIFT) positional distribution information dimension reduction
原文传递
Using multi-matching system based on a simplified deformable model of the human iris for iris recognition 被引量:2
10
作者 MING Xing , XU Tao , WANG Zheng-xuan 1 2 3 1. College of Computer Science and Technology, Nanling Campus,Jilin University, 5988 Renmin Street,Changchun 130022, P. R. China 2. College of Mechanical Science and Engineering, Nanling Campus,Jilin University, 5988 Renmin Street, Changchun 130022, P. R. China 3. College of Computer Science and Technology, Qianwei Campus,Jilin University, 10 Qianwei Road, Changchun 130012, P. R. China. 《Journal of Bionic Engineering》 SCIE EI CSCD 2004年第3期183-190,共8页
A new method for iris recognition using a multi-matching system based on a simplified deformable model of the human iris was proposed. The method defined iris feature points and formed the feature space based on a wa... A new method for iris recognition using a multi-matching system based on a simplified deformable model of the human iris was proposed. The method defined iris feature points and formed the feature space based on a wavelet transform. In the matching stage it worked in a crude manner. Driven by a simplified deformable iris model, the crude matching was refined. By means of such multi-matching system, the task of iris recognition was accomplished. This process can preserve the elastic deformation between an input iris image and a template and improve precision for iris recognition. The experimental results indicate the va- lidity of this method. 展开更多
关键词 iris recognition wavelet transform feature points deformable model
在线阅读 下载PDF
Summed volume region selection based three-dimensional automatic target recognition for airborne LIDAR 被引量:2
11
作者 Qi-shu Qian Yi-hua Hu +2 位作者 Nan-xiang Zhao Min-le Li Fu-cai Shao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第3期535-542,共8页
Airborne LIDAR can flexibly obtain point cloud data with three-dimensional structural information,which can improve its effectiveness of automatic target recognition in the complex environment.Compared with 2D informa... Airborne LIDAR can flexibly obtain point cloud data with three-dimensional structural information,which can improve its effectiveness of automatic target recognition in the complex environment.Compared with 2D information,3D information performs better in separating objects and background.However,an aircraft platform can have a negative influence on LIDAR obtained data because of various flight attitudes,flight heights and atmospheric disturbances.A structure of global feature based 3D automatic target recognition method for airborne LIDAR is proposed,which is composed of offline phase and online phase.The performance of four global feature descriptors is compared.Considering the summed volume region(SVR) discrepancy in real objects,SVR selection is added into the pre-processing operations to eliminate mismatching clusters compared with the interested target.Highly reliable simulated data are obtained under various sensor’s altitudes,detection distances and atmospheric disturbances.The final experiments results show that the added step increases the recognition rate by above 2.4% and decreases the execution time by about 33%. 展开更多
关键词 3D automatic target recognition point cloud LIDAR AIRBORNE Global feature descriptor
在线阅读 下载PDF
Optimal Deep Convolutional Neural Network with Pose Estimation for Human Activity Recognition 被引量:1
12
作者 S.Nandagopal G.Karthy +1 位作者 A.Sheryl Oliver M.Subha 《Computer Systems Science & Engineering》 SCIE EI 2023年第2期1719-1733,共15页
Human Action Recognition(HAR)and pose estimation from videos have gained significant attention among research communities due to its applica-tion in several areas namely intelligent surveillance,human robot interaction... Human Action Recognition(HAR)and pose estimation from videos have gained significant attention among research communities due to its applica-tion in several areas namely intelligent surveillance,human robot interaction,robot vision,etc.Though considerable improvements have been made in recent days,design of an effective and accurate action recognition model is yet a difficult process owing to the existence of different obstacles such as variations in camera angle,occlusion,background,movement speed,and so on.From the literature,it is observed that hard to deal with the temporal dimension in the action recognition process.Convolutional neural network(CNN)models could be used widely to solve this.With this motivation,this study designs a novel key point extraction with deep convolutional neural networks based pose estimation(KPE-DCNN)model for activity recognition.The KPE-DCNN technique initially converts the input video into a sequence of frames followed by a three stage process namely key point extraction,hyperparameter tuning,and pose estimation.In the keypoint extraction process an OpenPose model is designed to compute the accurate key-points in the human pose.Then,an optimal DCNN model is developed to classify the human activities label based on the extracted key points.For improving the training process of the DCNN technique,RMSProp optimizer is used to optimally adjust the hyperparameters such as learning rate,batch size,and epoch count.The experimental results tested using benchmark dataset like UCF sports dataset showed that KPE-DCNN technique is able to achieve good results compared with benchmark algorithms like CNN,DBN,SVM,STAL,T-CNN and so on. 展开更多
关键词 Human activity recognition pose estimation key point extraction classification deep learning RMSProp
在线阅读 下载PDF
Automatic Terrain Debris Recognition Network Based on 3D Remote Sensing Data
13
作者 Xu Han Huijun Yang +4 位作者 Qiufeng Shen Jiangtao Yang Huihui Liang Cancan Bao Shuang Cang 《Computers, Materials & Continua》 SCIE EI 2020年第10期579-596,共18页
Although predecessors have made great contributions to the semantic segmentation of 3D indoor scenes,there still exist some challenges in the debris recognition of terrain data.Compared with hundreds of thousands of i... Although predecessors have made great contributions to the semantic segmentation of 3D indoor scenes,there still exist some challenges in the debris recognition of terrain data.Compared with hundreds of thousands of indoor point clouds,the amount of terrain point cloud is up to millions.Apart from that,terrain point cloud data obtained from remote sensing is measured in meters,but the indoor scene is measured in centimeters.In this case,the terrain debris obtained from remote sensing mapping only have dozens of points,which means that sufficient training information cannot be obtained only through the convolution of points.In this paper,we build multi-attribute descriptors containing geometric information and color information to better describe the information in low-precision terrain debris.Therefore,our process is aimed at the multi-attribute descriptors of each point rather than the point.On this basis,an unsupervised classification algorithm is proposed to divide the point cloud into several terrain areas,and regard each area as a graph vertex named super point to form the graph structure,thus effectively reducing the number of the terrain point cloud from millions to hundreds.Then we proposed a graph convolution network by employing PointNet for graph embedding and recurrent gated graph convolutional network for classification.Our experiments show that the terrain point cloud can reduce the amount of data from millions to hundreds through the super point graph based on multi-attribute descriptor and our accuracy reached 91.74%and the IoU reached 94.08%,both of which were significantly better than the current methods such as SEGCloud(Acc:88.63%,IoU:89.29%)and PointCNN(Acc:86.35,IoU:87.26). 展开更多
关键词 Semantic segmentation low-precision point cloud large-scale terrain debris recognition
在线阅读 下载PDF
About a Method of Recognition of Race and Ethnicity of Individuals Based on Portrait Photographs
14
作者 Tofiq Kazimov Shafagat Mahmudova 《Intelligent Control and Automation》 2014年第3期120-125,共6页
This article is devoted to developing a recognition method of race and ethnicity of individual based on portrait photographs. The reference image is formed based on selected geometric points of the face and a special ... This article is devoted to developing a recognition method of race and ethnicity of individual based on portrait photographs. The reference image is formed based on selected geometric points of the face and a special algorithm for calculating the characteristic parameters of the images available in the database. Next, the original image is compared with the reference images of ethnic groups, and thus, the affiliation of the original image to a specific ethnic group is determined. 展开更多
关键词 recognition RACE ETHNICITY ETHNIC Group RACIAL Origin Identification points
暂未订购
Face Recognition from Incomplete Measurements via <i>l<sub>1</sub></i>-Optimization
15
作者 Miguel Argaez Reinaldo Sanchez Carlos Ramirez 《American Journal of Computational Mathematics》 2012年第4期287-294,共8页
In this work, we consider a homotopic principle for solving large-scale and dense l1underdetermined problems and its applications in image processing and classification. We solve the face recognition problem where the... In this work, we consider a homotopic principle for solving large-scale and dense l1underdetermined problems and its applications in image processing and classification. We solve the face recognition problem where the input image contains corrupted and/or lost pixels. The approach involves two steps: first, the incomplete or corrupted image is subject to an inpainting process, and secondly, the restored image is used to carry out the classification or recognition task. Addressing these two steps involves solving large scale l1minimization problems. To that end, we propose to solve a sequence of linear equality constrained multiquadric problems that depends on a regularization parameter that converges to zero. The procedure generates a central path that converges to a point on the solution set of the l1underdetermined problem. In order to solve each subproblem, a conjugate gradient algorithm is formulated. When noise is present in the model, inexact directions are taken so that an approximate solution is computed faster. This prevents the ill conditioning produced when the conjugate gradient is required to iterate until a zero residual is attained. 展开更多
关键词 SPARSE Representation l1Minimization Face recognition SPARSE Recovery INTERIOR point Methods SPARSE REGULARIZATION
在线阅读 下载PDF
Human Interaction Recognition in Surveillance Videos Using Hybrid Deep Learning and Machine Learning Models
16
作者 Vesal Khean Chomyong Kim +5 位作者 Sunjoo Ryu Awais Khan Min Kyung Hong Eun Young Kim Joungmin Kim Yunyoung Nam 《Computers, Materials & Continua》 SCIE EI 2024年第10期773-787,共15页
Human Interaction Recognition(HIR)was one of the challenging issues in computer vision research due to the involvement of multiple individuals and their mutual interactions within video frames generated from their mov... Human Interaction Recognition(HIR)was one of the challenging issues in computer vision research due to the involvement of multiple individuals and their mutual interactions within video frames generated from their movements.HIR requires more sophisticated analysis than Human Action Recognition(HAR)since HAR focuses solely on individual activities like walking or running,while HIR involves the interactions between people.This research aims to develop a robust system for recognizing five common human interactions,such as hugging,kicking,pushing,pointing,and no interaction,from video sequences using multiple cameras.In this study,a hybrid Deep Learning(DL)and Machine Learning(ML)model was employed to improve classification accuracy and generalizability.The dataset was collected in an indoor environment with four-channel cameras capturing the five types of interactions among 13 participants.The data was processed using a DL model with a fine-tuned ResNet(Residual Networks)architecture based on 2D Convolutional Neural Network(CNN)layers for feature extraction.Subsequently,machine learning models were trained and utilized for interaction classification using six commonly used ML algorithms,including SVM,KNN,RF,DT,NB,and XGBoost.The results demonstrate a high accuracy of 95.45%in classifying human interactions.The hybrid approach enabled effective learning,resulting in highly accurate performance across different interaction types.Future work will explore more complex scenarios involving multiple individuals based on the application of this architecture. 展开更多
关键词 Convolutional neural network deep learning human interaction recognition ResNet skeleton joint key points human pose estimation hybrid deep learning and machine learning
在线阅读 下载PDF
基于改进PointNet++的集装箱船绑扎眼板智能识别算法
17
作者 闫家文 陈震 +2 位作者 马誉贤 钮东辉 郝传宏 《船舶工程》 北大核心 2025年第11期145-152,共8页
[目的]为了对绑扎桥点云数据实现端到端智能识别,[方法]提出一种改进PointNet++的绑扎眼板智能识别算法。基于实船扫描获取的集装箱船绑扎桥点云数据,使用CloudCompare软件对绑扎眼板进行语义分割标注,构建LashingNet数据集,基于绑扎眼... [目的]为了对绑扎桥点云数据实现端到端智能识别,[方法]提出一种改进PointNet++的绑扎眼板智能识别算法。基于实船扫描获取的集装箱船绑扎桥点云数据,使用CloudCompare软件对绑扎眼板进行语义分割标注,构建LashingNet数据集,基于绑扎眼板理论模型构建综合损失函数,通过该数据集训练改进的PointNet++网络。[结果]结果表明,网络模型在LashingNet训练集和验证集上的收敛结果趋于稳定,在验证集上的总体准确率(OA)达到99.15%,平均交并比(mIoU)达到96.61%,在全新测试集上眼板有效识别率达到94.64%,证明了模型良好的泛化性。[结论]该方法具有良好的识别能力,在集装箱船绑扎眼板的智能识别领域有良好的应用潜力。 展开更多
关键词 船舶绑扎桥 船舶建造 三维点云 pointNet++ 智能绑扎识别
原文传递
Understanding Local Conformation in Cyclic and Linear Polymers Using Molecular Dynamics and Point Cloud Neural Network
18
作者 Wan-Chen Zhao Hai-Yang Huo +1 位作者 Zhong-Yuan Lu Zhao-Yan Sun 《Chinese Journal of Polymer Science》 2025年第5期695-710,共16页
Understanding the conformational characteristics of polymers is key to elucidating their physical properties.Cyclic polymers,defined by their closed-loop structures,inherently differ from linear polymers possessing di... Understanding the conformational characteristics of polymers is key to elucidating their physical properties.Cyclic polymers,defined by their closed-loop structures,inherently differ from linear polymers possessing distinct chain ends.Despite these structural differences,both types of polymers exhibit locally random-walk-like conformations,making it challenging to detect subtle spatial variations using conventional methods.In this study,we address this challenge by integrating molecular dynamics simulations with point cloud neural networks to analyze the spatial conformations of cyclic and linear polymers.By utilizing the Dynamic Graph CNN(DGCNN)model,we classify polymer conformations based on the 3D coordinates of monomers,capturing local and global topological differences without considering chain connectivity sequentiality.Our findings reveal that the optimal local structural feature unit size scales linearly with molecular weight,aligning with theoretical predictions.Additionally,interpretability techniques such as Grad-CAM and SHAP identify significant conformational differences:cyclic polymers tend to form prolate ellipsoid shapes with pronounced elongation along the major axis,while linear polymers show elongated ends with more spherical centers.These findings reveal subtle yet critical differences in local conformations between cyclic and linear polymers that were previously difficult to discern,providing deeper insights into polymer structure-property relationships and offering guidance for future polymer science advancements. 展开更多
关键词 Molecular dynamics simulation point cloud Interpretable deep learning Conformational recognition
原文传递
基于PointNet的钢板毛坯垛点云分割
19
作者 林振杨 《机电工程技术》 2025年第1期152-156,共5页
钢板毛坯垛拆垛工序中,钢板毛坯分层厚度的估计是推钢机准确且安全执行推钢动作的关键;当前不少企业此道生产工序仍主要靠操作员人工观察的方式估算钢板厚度及与传送辊道的相对高度,其估算不准易导致碰撞,造成输送设备损坏生产中断。提... 钢板毛坯垛拆垛工序中,钢板毛坯分层厚度的估计是推钢机准确且安全执行推钢动作的关键;当前不少企业此道生产工序仍主要靠操作员人工观察的方式估算钢板厚度及与传送辊道的相对高度,其估算不准易导致碰撞,造成输送设备损坏生产中断。提出一种钢板毛坯垛智能分层方法,该方法结合现场工况环境采用激光雷达,对钢板毛坯垛进行三维点云成像,然后对采集的点云数据,用PointNet神经网络框架进行特征识别、分层分割与提取,最后对分割的不同层根据标定值,换算成真实厚度。根据现场实验结果表明,PointNet对钢板毛坯垛分割的识别率达到了87.4%,厚度估算误差低于1.2cm,根据钢厂钢板毛坯规格表(3种规格150、160、180cm)可以准确估计出钢板毛坯厚度的规格,识别速度15帧/s,满足现场工况要求。 展开更多
关键词 钢板毛坯垛 点云分割 特征识别 pointNet
在线阅读 下载PDF
基于奇异平面空间染色镶嵌的空间点模式识别与特征提取
20
作者 刘菁 朱渭宁 《深圳大学学报(理工版)》 北大核心 2026年第1期101-109,共9页
为扩展空间点可识别模式的多样性,基于空间染色模型(spatial chromatic model,SCM),分析奇异空间染色镶嵌的空间染色码与空间点模式之间的对应关系,发现空间码的数值大小及统计特征可指示空间点的分布模式.该方法不仅能识别点模式中常... 为扩展空间点可识别模式的多样性,基于空间染色模型(spatial chromatic model,SCM),分析奇异空间染色镶嵌的空间染色码与空间点模式之间的对应关系,发现空间码的数值大小及统计特征可指示空间点的分布模式.该方法不仅能识别点模式中常见的随机、聚类等特性,也能识别共线、共圆、对称等特殊模式,且有利于将点模式识别与SCM的其他空间分析功能结合,在一个统一框架内完成实体与空间关系的分析与处理.研究结果可为空间点模式识别提供新的理解思路与分析方法. 展开更多
关键词 模式识别 空间点模式 空间染色模型 聚类分析 奇异空间 计算几何
在线阅读 下载PDF
上一页 1 2 61 下一页 到第
使用帮助 返回顶部